Silver halide emulsion containing an organic selenium compound antifogging agent

ABSTRACT

Light-sensitive materials comprising a silver halide emulsion layer and a compound having the formula:

United States Patent Field of Search. ..96/109, 107, 1 10 Pollet et al. 1 Apr. 17, 1973 1 SILVER HALIDE EMULSION 1 References Citefl M m CONTAINING AN ORGANIC UNITED STATES PATENTS SELENIUM' COMPOUND 2,057,764 10 1936 Brunken ..96/109 ANTIFOGGING AGENT 3,397,986 8/1968 Millikon et a1. ..96 .109 I 3,226,232 12/1965 Dersch et a1. ..96/109 [75] Inventors w P Yf 2,385,762 9 1945 Mueller ..96/109 Frans Wfllems, u i both of l,623,499 4/1927 Sheppard et a1... ..96/l07 Belgium 1,602,592 10/1926 Sheppard et a.l....'. ..96/107 [73] Assignee: vGe vaei't-Agfaai N.\ Mortsel, Belg1- Primary Examiner Norman G. Tiorchin um I k Assistant Examiner-Won H. Louie, Jr.

[22] Filed: Mar. 6, 1970 M Attorney-Brufsky, Staas, Breiner and Halsey [21] ApPl. NCiJ 17,304 57 ABSTRACT l Light-sensitive materials comprising a silver halide v F g Appllcatlon 9 Data emulsion layer and a compound having the formulai July 3, 1969 Great Britain ..12,234/69 52 US. Cl. .;96/l09, 96/107, 96/108, wherein: 1 96/52 96/94 Q stands for selenium or sulphur, and I t Cl 1 G05c'1/34 each of R and R (the same or different) stands fo [58] n an alkyl g p an aralkyl g p or an y group The compound of the general formula inhibits fogging and/or bron zing and/or stabilizes the emulsion.

10 Claims, No Drawings ment which is dependent on a whole series of circumstances and factors namely on the nature of the emulsions, on their age, on the conditions under which theyhave been stored, on the development conditions, etc. For particular development conditions the fog tends to be greater as the time of storage and the temperature and relative humidity of the atmosphere in which the emulsions arestored are increased.

It is also known that the silver image formed after exposure undergoes a degradation, by which is meant a shift and a decrease of intensity of the image-tone during the finishing to a visible image e.g. under the influence of ingredients used in the developing bath, the fixing bath, the coloring'bath, and so on. This degradation mainly appears on drying the developed images, whereby a decrease of density and of gradation takes Cl- -Se-Se- -Cl 4 COOH COOH HOOC- -SeSe- -COOH.

J. Am. Chem. Soc. 82, 2762 (1960).

place and an undesired color or metallic gloss of the developed silver, the so-called plumming", appears. This phenomenon is particularly pronounced when the photographic images are submitted to hot-glazing or mechanical drying at elevated temperature.

Several compounds have been proposed for use as stabilizers, antifoggants and antibronzing agents. The greater part of these compounds, however, usually exert a strong desensitizing'effect on the emulsion.

, It has now been found that compounds corresponding to the following general formula wherein v Q stands for selenium or sulphur, and I each of R, and R (the same or different) stands for an alkyl group, an aralkyl or an aryl group including these groups carrying further substituents such as halogen e.g. chlorine and bromine, carboxyl, nitro, etc. are effective antibronzing agents and exert a fog-in hibiting action on light-sensitive photographic emulsions without giving rise to an appreciable desensitization thereof.

The compounds having the structures listed below are representatives of those falling within the scope of the above general formula. They can be prepared as described in the literature referred to.

Ben, 65, 812 (1932).

J. Chem. 800., 1364 (1926).

J. chem. $00., 2331 (1952).

J. Chem. 800. 2280 1928).

Houben-Weyl Methoden der OrganischenChemie Band XI, 1955, p. 1095.

J. Chem. 800., 1364 (1926).

Bull. Soc. Chim., 245 (1960).

Ben, 92, 40 1050 J. Org. Chem. 33, 230 (1968).

Compound 11 was prepared from the Grignard reagent of m-chloro-bromobenzene in anhydrous ether treated with an equimolecular amount of selenium by refluxing for 2 hours with stirring. The mixture was acidified with diluted hydrochloric acid whereupon the ether layer was separated, dried over sodium sulphate and filtered. An air current was conducted through the solution and the latter was distilled.

Compound 13 was prepared as follows 0.02 mole of phenylethylselenocyanate in 50 ml of methanol was admixed with a solution of 0.5 g of sodium in ml of methanol. The mixture was refluxed for 2 hours and an oil formed. After dilution with 75 ml of water, the mixture was extracted with ether. The ether extract was dried over sodium sulphate, filtered and concentrated by evaporation. Yield 1.7g of yellow oil.

The phenylethylsenocyanate used was prepared refluxing with stirring for 6 hours a mixture of 0.1 mole of bromethylbenzene and 0.1 mole of potassium selenocyanate in lOO ml of acetone. The potassium bromide formed was filtered off by suction and the filtrate concentrated by evaporation. The residual oil was distilled under reduced pressure. Yield 18 g.

The compounds according to the present invention are generally incorporated into the silver halide emulsion layer of the light-sensitive material. The way in which the compounds of use according to the invention are added to the emulsions is not critical and the addition can be made during no matter what step of emulsion preparation; they can be added before or after the emulsion has been optically sensitized, preferably just before coating of the emulsion on a suitable support such as for example paper, glass or film.

Instead of incorporating the compounds of the invention into the emulsion layer they can also be incorporated into another layer of the photographic material, e.g. a gelatin antistress layer or intermediate layer, which is in water-permeable relationship with the said emulsion layer.

The compounds of use according to the present invention may be incorporated into any type of light-sensitive material comprising a silver halide emulsion layer e.g. a spectrally sensitized or non-sensitized silver halide emulsion layer, a silver halide emulsion layer of use in diffusion transfer processes for the production of silver images, an X-ray emulsion layer, and an emulsion layer sensitive to infra-red radiation. They may be incorporated into high speed negative material as well as into rather low speed positive materials. Various silver salts may be used as light-sensitive salt e.g. silver bromide, silver iodide, silver chloride, or mixed silver halides e.g. silver chlorobromide or silver bromo-iodide.

The silver halides are dispersed in the common hydrophilic colloids such as gelatin, casein, zein, polyvinyl alcohol, carboxymethylcellulose, alginic acid, etc., gelatin being, however, favored.

The amount of compound according to the present invention employed in the light-sensitive silver halide material depends on the particular type of emulsion and the desired effect and can vary within very wide limits. The optimum amount to be added is best determined for each particular type of emulsion by trial.

' When used as antifoggant, the most suitable concentration of compound according to the present invention is generally comprised between 0.01 millimole and l millimole, preferably between 0.05 millimole and 0.25 millimole per mole of silver halide. When used as antibronzing agent the compounds according to the present invention are preferably used in amounts from some mg to about 500 mg per sq.m. of light-sensitive printing material.

The light-sensitive emulsions may be chemically as well as optically sensitized. They may be chemically sensitized by effecting the ripening in the presence of small amounts of sulphur containing compounds such as allyl thiocyanate, allyl thiourea, sodium thiosulphate, etc. The emulsions may also be sensitized by means of reductors for instance tin compounds as described in our British Patent Specification 789,823 and small amounts of noble metal compounds such as gold, platinum, palladium, iridium, ruthenium and rhodium.

Furthermore, the emulsions may also comprise compounds which sensitize the emulsion by development acceleration for example alkylene oxide polymers. These alkylene oxide polymers may be of various type. Various derivatives of alkylene oxides may be used to sensitize the silver halide emulsions e.g. alkylene oxide condensation products as described among others in US. Pat. Nos. 2,531,832 and 2,533,990 in U.K.Patent Specifications 920,637, 940,051, 945,340 and 991,608 and in Belgian Patent Specification 648,710. Other compounds that sensitize the emulsion by development acceleration and that are suitable for use in combination with the compounds of use according to the invention are the onium derivatives of amino-N-oxides as described in U.K.Patent Specification 1,121,696.

In conjunction with light-sensitive materials comprising compounds according to the above general formula there may also be used known stabilizers for instance heterocyclic nitrogen containing thioxo compounds such as benzothiazoline-Z-thione and l-phenyl-A tetrazoline-S-thione, mercury compounds such as those described in Belgian Patent Specifications 524,121 and 677,337 and in published Dutch Patent Application 67 15 932 and compounds of the hydroxytriazolo pyrimidine type (hydroxyazaindolizines), particularly in extreme storage and development circumstances.

Other addenda such as hardening agents, wetting agents, plasticizers, color couplers, developing agents and optical sensitizers can be incorporated into the emulsion in the usual way.

The following examples illustrate the stabilizing or fog-inhibiting action of compounds corresponding to the above general formula. In these examples, the values I and II given for the speed are exposure values corresponding with density 0.1 above fog and density 1 above fog respectively; a decrease of the value by 30 means a doubling of the speed.

Example 1 A conventional photographic gelatino silver bromoiodide emulsion (4.5 mole percent iodide) comprising per kg an amount of silver halide equivalent to 50 g of silver nitrate was divided into two portions A and B. To emulsion portion B was added per kg of emulsion 0.03 mmole of compound 2. Then the emulsions were coated on a conventional support and dried.

The values of speed, gradation and fog of the materials formed were determined shortly after preparation 'and after incubation for 5 days at 57C and 34 percent relative humidity. The values obtained are listed in the table below.

Development occurred at 20C for 5 min. in a developing solution having the following composition water 800 ccs p-monomethylaminophenol sulphate 1.5 g sodium sulphite (anhydrous) 50 g hydroquinone 6 g sodium carbonate (anhydrous) 32 g potassium bromide 2 2 water to make 1000 ccs Example 1 was repeated with the difference that the emulsion was divided'into three aliquot portions to which the compounds listed in the table below were added in the concentration given. The sensitometric results obtained are listed in the following table.

Compound added fresh material incubated material per kg of emulsion fog gradspeed fog gradspeed ation l ation 1 none 0.13 1.52 52 144 0.77 1.11 69 172 0.03 millimole 0.11 1.47 55 149 0.43 1.31 57 156 of compound 4 0.03 millimole 0.11 1.39 54 152 0.45 l.l7 54 159 of compound 3 percent of relative humidity whereupon they were exposed to X-rays with an X-ray radiation source of 80 kV and developed for 8 min. at 20C in a common X- ray developer having the following composition water 800 ccs p-monomethylaminophenol hemisulphate 4 g hydroquinone 10 g anhydrous sodium sulphite 65 g anhydrous sodium carbonate 45 g potassium bromide 5 g water up to 1000 ccs The values of the fog produced in the stored materials as compared with the values of the fog produced in the freshly prepared materials are listed in the following table.

Compound added per fog in fresh fog in stored kg of emulsion materials materials none 0.19 1.99 0.2 mmole of compound 4 0.09 0.34 0.6 mmole of compound 11 0.05 0.05

Example 4 A gelatino silver bromoiodide emulsion as described in example 3 was divided into four aliquot portions. To each portion, one of the compounds listed in the table below was added in the concentration given.

The emulsions were then further treated as described in example 3 and the resulting materials were conditioned in a moist atmosphere of about percent of relative humidity. Thereupon the materials were packed in aluminum laminated paper and stored for 5 days at 57C. I a v The values of the fog produced in the stored materials as compared with the values of the fog produced in the freshly prepared materials are listed in the follow ing table. g

Development occurred as described in example 3.

fog produced compound added per fog produced in kg of emulsion fresh materials in stored materials none 0.19 2.47

0.2 mmole of compound 4 0.09 0.28

0.6 mmole of compound 11 0.05 0.05

The following examples illustrate the antibronzlng action of the compounds corres'ponding to the above general formula in photographic printing material. Example 5 Material 1 A gelatino silver chloroiodide emulsion (0.4 mole percent of iodide), prepared with aproportion of silver nitrate to gelatin of 1 to 3 was applied to a barytacoated paper support in such a way that after drying an amount of silver halide, equivalentto 1.9 g of silver nitrate was present per sq.m of light-sensitive material. The light-sensitive emulsion layer was overcoated with a thin gelatin covering layer which was hardened afterwards.

Material 2 -Material 2 was prepared as material 1 with the difference, however, that per kg of light-sensitive emulsion ready for coating, 1.8 mmol of compound 9 was added from a solution in ethylene glycol monomethyl ether.

Material 3 Material 3 was prepared as material 1 with the difference, however, that per kg of light-sensitive emulsion ready for coating, 1.8 mmol of compound 10 was added from a solution in ethylene glycol monomethyl ether.

Material4 Material 4 was prepared as material 1 with the difference, however, that per kg of lightsensitive emulsion ready for coating, 1.8 mmol of compound 11 was added from a solution in ethylene glycol monomethyl ether.

Material 5 i i Material 5 was prepared as material 1 with the difference, however, that per kg of light-sensitive emulsion ready for coating, 1.8 mmol of compound 3 was added from a solution in isopropylalcohol.

Strips of each of these materials were exposedand developed for 5 minutes at 20C in a bath of the follow ing composition hydroquinone 6 g anhydrous sodium carbonate 32 g potassium bromide 2 g water up to 1000 ccs The strips were rinsed and then fixed for minutes at room temperature in the following composition water 800 ccs anhydrous sodium thlosulphate 120 g potassium metabisulphite 25 g water to make 1000 ccs The strips were then pressed for 6 minutes with their light-sensitive side to a polished plate of 80C.

The density of the various material strips was measured with a Macbeth densitometer before as well as after hot-glazing. The following results were attained.

Density before Density after hot-glazing hot-glazing 1st test material 1 2.04 1.59 material 2 2.05 1.96 2nd test material 1 1.96 1.67 material 3 1.99 1.86 3rd test material 1 1.98 1.64 material 4 2.01 1.89 material 5 1.96 1.82

Example 6 Material 1 A gelatino silver bromochloride emulsion (46 mole percent of chloride), prepared with a proportion of silver nitrate to gelatin of l to 3 was applied to a barytacoated paper support in such a way that after drying an amount of silver halide, equivalent to 2.6 g of silver nitrate was present per sq.m of light-sensitive material. The light-sensitive emulsion layer was overcoated with a thin gelatin covering layer which was hardened afterwards.

Material 2 Material 2 was prepared as material 1 with the difference, however, that per kg of light-sensitive emulsion ready for coating, 1.8 mmol of compound 9 was added from a solution in ethylene glycol monomethyl ether.

Material 3 Material 3 was prepared as material 1 with the difference, however, that per kg of light-sensitive emulsion ready for coating, 1.8 mmol of compound 10 was added from a solution in ethylene glycol monomethyl ether.

Material 4 Material 4 was prepared as material 1 with the dif- Density before hot-glazing Density after hot-glazin g 1st test material 1 1.85 1.70 material 2 1.87 2.00 2nd test material 1 1.84 1.76 material 3 1.78 1.84 3rd test material 1 1.84 1.68 material 4 1.83 1.93 material 5 .8 1.78

Example 7 Material 1 A gelatino silver bromochloroiodide emulsion (9 mole percent of chloride and 1 mole percent of iodide), prepared with a proportion of silver nitrate to gelatin of l to 1.8 was applied to a baryta-coated paper support in such away that after drying an amount of silver halide, equivalent to 2.5 g of silver nitrate was present per sq.m of light-sensitive material. The light-sensitive emulsion layer was overcoated with a thin gelatin covering layer which was hardened afterwards.

Material 2a Material 2a was prepared as material 1 with the difference, however, that per kg of light-sensitive emulsion ready for coating, 0.6 mmol of compound 9 was added from a solution in ethylene glycol monomethyl ether.

Material 2b Material 2b was prepared as material 1 with thedifference, however, that per kg of light-sensitive emulsion ready for coating, 1.8 mmol of compound 9 was added from a solution in ethylene glycol monomethyl ether.

Strips of each of these materials were further treated as described in example 5.

The following results were attained Density before Density after hot-glazing hot-glazing 1st test material 1 1.90 1.82 material 2a 1.92 1.95 material 2b 1.87 2.08

We claim:

1. Photographic material comprising a support and at least one light-sensitive silver halide emulsion layer comprising in said emulsion layer and/or in at least one water-permeable layer coated at the same side of the support as the said emulsion layer and being in waterpermeable relation with said emulsion layer, at least one compound corresponding to the following general formula:

4. Photographic material according to claim ll,

wherein said emulsion layer is a gelatino silver halide emulsion layer.

5. Photographic material according to claim 1 according to according to according to claim claim claim claim ll) zo 10. Photographic material according to claim 1 wherein said compound has the formula:

COOH COOH UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,72 125 DATED April 17, 1973 INVENTOR(S) Robert Joseph POLLET ET AL It is certified that error appears in the ab0ve-identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading, [30] Foreign Application Priority Data, "July 3, 1969" should read March 7, 1969 Signed and Sealed this Seventeenth Day of May 1977 [SEAL] AIIGSI.

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner oj'larenrs and Trademarks 

2. Photographic material according to claim 1, wherein said material also comprises a stabilizer of the hydroxytriazolo-pyrimidine type.
 3. Photographic material according to claim 1, wherein said material also comprises a development accelerator of the polyoxyalkylene type.
 4. Photographic material according to claim 1, wherein said emulsion layer is a gelatino silver halide emulsion layer.
 5. Photographic material according to claim 1 wherein Q is Se.
 6. Photographic material according to claim 1 wherein Q is S.
 7. Photographic material according to claim 1 wherein R1 and R2 are alkyl.
 8. Photographic material according to claim 1 wherein R1 and R2 are aryl.
 9. Photographic material according to claim 1 wherein said compound has the formula:
 10. Photographic material according to claim 1 wherein said compound has the formula: 